The number of automobiles being operated in the world is continuing to increase. This increase in automobiles has significantly increased the worldwide air pollution problem. In order to control this air pollution problem from automobiles, many countries have begun to regulate the exhaust emissions from automobiles. In fact, the exhaust emissions standards are constantly becoming stricter each year. For example, California regulators have recently passed a law requiring 2% of all vehicles sold in California to be "zero-emissions" or electric powered by 1998. Failure to meet the new emission standard would result in significant fines to automobile manufacturers selling automobiles in California. Accordingly, automobile manufacturers' ability to sell automobiles in California will be hurt if they do not produce an automobile with zero-emissions.
In view of these increasingly stricter emission requirements, automobile manufacturers are beginning to develop electric powered vehicles. Accordingly, it will be necessary to provide the owners of the electric vehicles with a safe and easy way of recharging their batteries. Moreover, electric vehicles have a limited range of travel before requiring their batteries to be recharged. Thus, recharging stations will be needed which are conveniently located and easy to operate in substantially the same manner in which gas stations are currently available for gas powered vehicles.
Preferably, recharging stations should also be available at the residences of owners of electric vehicles so that they may charge their electric vehicles at home as well as at various locations away from the owners' homes. Typically, residential homes utilize low amperage alternating current which can only provide a slow or low level charge for recharging the electric vehicle commercial recharging stations, on the other hand, can typically be equipped with high amperage direct electrical current which can provide a fast or high level charge for recharging electric vehicles. Therefore, it would be highly desirable to have electric vehicles which are capable of selectively receiving direct electrical current for a fast, high level charge as well as alternating electrical current for a slow, low level charge. In either application, the electrical connectors for the recharging station and the electric vehicle should operate in substantially the same manner in which gas powered vehicles are refueled.
One example of an electric vehicle and a recharging station for recharging the batteries of electric vehicles is disclosed in U.S. Pat. No. 4,158,802 to Rose, II. The electric vehicle and the recharging station disclosed in the patent issued to Rose, II have many drawbacks. For instance, the contact surface of the vehicle is exposed to the environment which can cause the electrical contact surfaces of the vehicle to corrode. Also, the electrical contact surfaces of the vehicle and the recharging station are exposed to the driver such that the driver of the vehicle could accidentally touch one of the electric contacts and receive an electrical shock. Furthermore, this recharging station would require all electric vehicles to be manufactured within a certain range of sizes and shapes.
Accordingly, many attempts have been made to use inductive power couplings to recharge the batteries of an electric vehicle. Inductive power couplings transfer power from a power source to the vehicle by means of a magnetic field that extends through an air gap. However, these inductive power couplings have certain disadvantages. For example, research is currently being conducted on the harmful effects on humans of magnetic fields, such as created by inductive couplings. Moreover, existing inductive power couplings are not capable of transferring high amperage which is necessary to provide a fast charge to the vehicle's battery.
Examples of inductive power couplings are disclosed in the following patents: U.S. Pat. No. 4,347,472 to Lemelson; U.S. Pat. No. 4,800,328 to Bolger et al; U.S. Pat. No. 5,157,319 to Klonte et al; Japanese patent application 63-287607 to Matsuoka; German patent 23 30 255; and Japanese patent application 58-69404 to Yamada.
In view of the above, it is apparent that there exists a need for an electrical connector assembly for transferring energy by conduction to electric vehicles from electrical recharging stations which will overcome the above problems of the prior art, and which are safe and convenient to operate as well as capable of selectively receiving both direct electrical current and alternating electrical current. This invention addresses these needs in the art along with other needs which will become apparent to those skilled in the art once given this disclosure.